In power transmission systems and then especially in High Voltage Direct Current (HVDC) power transmission systems, the current running through electrical components can be very high. Typical such components are current valve components like thyristors and Insulated Gate Bipolar Transistors (IGBTs). Due to these large currents, the components can generate large amounts of heat and therefore they need cooling. The way that they are cooled is therefore very important.
One cooling device in this field is described in WO 2007/149023. Here groups of electrical components to be cooled are placed in rows in a column in contact with cooling blocks. A cooling block is here provided for one or more rows including two groups of electrical components.
However, the normal way to cool components in HVDC systems is through using a cooling element or heat sink provided between the components and cooling the components in parallel using a cooling medium supplied in parallel to the cooling elements.
One problem with this approach is that a large amount of cooling medium may be used. The components may furthermore generate different amounts of heat and therefore the cooling requirements may differ.
There is therefore a need for providing a cooling which uses less cooling medium as well as considers the varying cooling requirements of the component.